Spring migration phenology and arrival conditions of the Eastern Bonelli's Warbler and the Semi-collared Flycatcher at a small Greek island

Abstract

In this study, we examined the spring migration phenology and arrival body mass and fat score of two long-distance migrants, the Eastern Bonelli's Warbler Phylloscopus orientalis and the Semi-collared Flycatcher Ficedula semitorquata at a small Greek island. Our data indicate a regular and early spring passage of both species through the area, with the Semi-collared Flycatcher peaking in late March and early April and the Eastern Bonelli's Warbler about a week later. The arrival body masses of both species were lower than any other mean value of body mass previously reported. This, along with the low fat loads of both species, indicates that the birds' reserves are depleted after crossing the Mediterranean Sea and suggests that they had probably not refuelled after the desert crossing. © 2013 Copyright British Trust for Ornithology.